Flashing BIOS from Linux

This article aims on providing information on flashing your system BIOS under Linux. Most manufacturers provide a Windows executable or a BIOS executable that can only be run under Windows. However, there are a few utilities, that allow you to upgrade your system BIOS under Linux.

Warning: Flashing motherboard BIOS is a dangerous activity that can render your motherboard inoperable! While the author of this article has successfully run this procedure many times, your mileage may vary. Be careful! You may want to consider updating microcode instead if it is supported by your system.

BiosDisk

Installation

Usage

To use the biosdisk utility to create a BIOS flash image, first download the latest raw BIOS image for your system from your manufacturer's website. Make sure however, that you always get the BIOS executable and NOT the Windows executable. You then have one of several options: create a floppy, create a dd floppy image, create a user-installable distribution-specific package (e.g. RPM), or actually install the image for your bootloader.

The mkfloppy action will create the biosdisk image and write it directly to a floppy disk. Usage is the following:

The mkpkg action will create the floppy image, and use it to create a user-installable package specific to the distribution (example: RPM). When the package is installed, it will use the distribution's built-in tools to update the system's bootloader so that the user can boot to the image from the hard drive to flash the BIOS, without needing a floppy drive. Currently only Red Hat/Fedora RPM packages are supported. Usage is as follows:

The install action will create the biosdisk image, copy the image file to /boot, and then update the bootloader with an entry for the image. Then all the user has to do is boot the system and select the image to flash the BIOS; this will load the biosdisk image directly from the hard drive and flash the BIOS.

biosdisk install [-o option] [--name=] /path/to/{.exe | .img}

Flashrom

Flashromis a utility for identifying, reading, writing, verifying and erasing flash chips. It is designed to flash BIOS/EFI/coreboot/firmware/optionROM images on mainboards, network/graphics/storage controller cards, and various programmer devices.

Unetbootin

You should format a pendrive with FAT16 and flag it as "boot" (you may do this through a GUI with gparted, qtpartedAUR or partitionmanagerAUR). Then, after mounting the flash drive, select under distribution FreeDOS and your mounted stick. The app will automatically download the image for you and copy it to the drive. Finally, you may copy everything you want to flash there (BIOS, firmwares, etc).

If you want to do it the hard way, keep reading. ;)

Gentoo

Check out FreeDOS Flash Drive on the Gentoo Wiki if you want to create a bootable FreeDOS Flash drive.

Images that are too large for a floppy

If your flash image is too large for a floppy, go to the FreeDos bootdisk website, and download the 10Mb hard-disk image. This image is a full disk image, including partitions, so adding your flash utility will be a little trickier:

You can do some simply maths now: block size (usually 512) times the start of the first partition. At time of writing, the first partition starts at block 63. This means that the partitions starts at offset 512 * 63 = 32256:

# mount -o offset=32256 /dev/loop0 /mnt

Now you can copy your flash utility onto the filesystem as normal. Once you're done:

# umount /mnt
# losetup -d /dev/loop0

The image can now be copied to a USB stick for booting, or booted as a memdisk as per normal instructions.

Usage

Step 1: Download FreeDOS boot disk floppy image
We are fortunate that guys at FDOS site have prepared one suitable for us. Use the OEM Bootdisk version, the one with just kernel and command.com, because it leaves more free space on disk for the flash utility and new BIOS image. After you download the image, you need to decompress it. In other words:

Requirement for this step is that you have support for the vfat and loop file systems in the kernel. Or you can have those features compiled as modules. In the latter case, load the modules before the next step, like this.

modprobe vfat
modprobe loop

Consult /proc/fileystems to see if you have the needed file systems supported. If you do, you should be able to "loop mount" the floppy disk image to some temporary path:

mkdir /tmp/floppy
mount -t vfat -o loop FDOEM.144 /tmp/floppy

If the mount went without errors, copy BIOS flash utility and new BIOS image to the mounted floppy disk image. You'll probably have to unzip the archive you downloaded from your motherboard vendor site, to get to those two files. Here's just an example for my motherboard (in your case, files will have different names, of course):

Next step is to burn the floppy image to a CD/DVD-RW media, but in a way that it can be booted afterwards. First we need to make a bootable CD image, and then burn it. Notice that on some modern distributions, cdrecord is renamed to wodim, and mkisofs to genisoimage, but the parameters below should be the same.

mkisofs -o bootcd.iso -b FDOEM.144 FDOEM.144
cdrecord -v bootcd.iso

Alternative Step 3: Add your image to Grub's menu.
You will need to install syslinux and copy memdisk to /boot, and put your image there as well.

Finally reboot your machine, make sure that your CD drive is first in the boot sequence, and then run your BIOS upgrade procedure when the CD boots. If using the GRUB method, just choose the new entry on the list, and it should boot into FreeDOS.